From the point of view of attracting more developers, a python
importer seems the best solution, also since there's good python
utility code already there from other IO addons. However from what I
can see the bpycollada importer is still at prototype level.

One concern I have with the bpycollada importer is the use of numpy and
datetime modules by pycollada which it's based on. Particularly numpy as
it's use seems to be for things like matrix transforms and things that
are already possible with bpy. Having an extra dependancy to duplicate
features just seems wrong to me.. But the alternative is forking
pycollada and rewriting a large chunk to use blender specific features.

pycollada also uses pil for some features and that's not available for
python 3.. I've not looked closely at how much of a problem that would
cause though.